@article{10_4064_aa134_3_1,
     author = {John L. Simons},
     title = {Exotic {Collatz} cycles},
     journal = {Acta Arithmetica},
     pages = {201--209},
     publisher = {mathdoc},
     volume = {134},
     number = {3},
     year = {2008},
     doi = {10.4064/aa134-3-1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa134-3-1/}
}